function s(){
	// 页面初次渲染的时候，小计会是每个商品的单价*数量
	let tr = document.querySelectorAll('#table tr');
	// 总价：
	let all = document.querySelector("#all");
	let allnum = 0

	for (let i = 0; i < tr.length; i++){
		// console.log("单价");
		// console.log("tr[i].children[2].children[0].innerHTML");
		// console.log("数量");
		// console.log("tr[i].children[3].children[0].value");
		// console.log("小计");
		// console.log("tr[i].children[4].children[0]")

		// 单价
		var price = tr[i].children[2].children[0].innerHTML
		// 数量
		var num = tr[i].children[3].children[0].value
		// 小计
		var total = tr[i].children[4].children[0].innerHTML = price * num

		console.log(total)
		allnum += total
	}
		console.log(allnum);
		// 页面初次渲染的时候，小计的总和赋值给总价
		all.innerHTML = allnum.toFixed(2)
	}
	s()

	// 只要数量的input内容发生改变，小计和总价就会更新
	let num_all = document.querySelectorAll('#table .num')
	for (let j = 0; j < num_all.length; j++){
		num_all[j].addEventListener('change',s)
	}

	// 删除操作之后，再根据小计计算总价
	let del_all = document.querySelectorAll('#table .del')
	for (let k = 0; k < del_all.length; k++){
		del_all[k].addEventListener('click',function(){
			console.log(this.parentNode.parentNode.parentNode)
			console.log(this.parentNode.parentNode)
			this.parentNode.parentNode.parentNode.removeChild(this.parentNode.parentNode)
			s()
		})
	}


